For DFPV, we optimize the model using Adam [1]} with learning rate = 0.001, \(\beta _1=0.9\) , \(\beta _2=0.999\)  and \(\varepsilon = 10^{-8}\) . Regularizers \(\lambda _1, \lambda _2\)  are both set to 0.1 as a result of the tuning procedure described in Appendix . Network structure is given in Tables REF , REF ,REF .
